kernel/freebsd/contigmem/contigmem.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <sys/cdefs.h>
   6 __FBSDID("$FreeBSD$");
   7
   8 #include <sys/param.h>
   9 #include <sys/bio.h>
  10 #include <sys/bus.h>
  11 #include <sys/conf.h>
  12 #include <sys/kernel.h>
  13 #include <sys/malloc.h>
  14 #include <sys/module.h>
  15 #include <sys/proc.h>
  16 #include <sys/lock.h>
  17 #include <sys/rwlock.h>
  18 #include <sys/mutex.h>
  19 #include <sys/systm.h>
  20 #include <sys/sysctl.h>
  21 #include <sys/vmmeter.h>
  22 #include <sys/eventhandler.h>
  23
  24 #include <machine/bus.h>
  25
  26 #include <vm/vm.h>
  27 #include <vm/pmap.h>
  28 #include <vm/vm_param.h>
  29 #include <vm/vm_object.h>
  30 #include <vm/vm_page.h>
  31 #include <vm/vm_pager.h>
  32 #include <vm/vm_phys.h>
  33
  34 struct contigmem_buffer {
  35         void           *addr;
  36         int             refcnt;
  37         struct mtx      mtx;
  38 };
  39
  40 struct contigmem_vm_handle {
  41         int             buffer_index;
  42 };
  43
  44 static int              contigmem_load(void);
  45 static int              contigmem_unload(void);
  46 static int              contigmem_physaddr(SYSCTL_HANDLER_ARGS);
  47
  48 static d_mmap_single_t  contigmem_mmap_single;
  49 static d_open_t         contigmem_open;
  50 static d_close_t        contigmem_close;
  51
  52 static int              contigmem_num_buffers = RTE_CONTIGMEM_DEFAULT_NUM_BUFS;
  53 static int64_t          contigmem_buffer_size = RTE_CONTIGMEM_DEFAULT_BUF_SIZE;
  54
  55 static eventhandler_tag contigmem_eh_tag;
  56 static struct contigmem_buffer contigmem_buffers[RTE_CONTIGMEM_MAX_NUM_BUFS];
  57 static struct cdev     *contigmem_cdev = NULL;
  58 static int              contigmem_refcnt;
  59
  60 TUNABLE_INT("hw.contigmem.num_buffers", &contigmem_num_buffers);
  61 TUNABLE_QUAD("hw.contigmem.buffer_size", &contigmem_buffer_size);
  62
  63 static SYSCTL_NODE(_hw, OID_AUTO, contigmem, CTLFLAG_RD, 0, "contigmem");
  64
  65 SYSCTL_INT(_hw_contigmem, OID_AUTO, num_buffers, CTLFLAG_RD,
  66         &contigmem_num_buffers, 0, "Number of contigmem buffers allocated");
  67 SYSCTL_QUAD(_hw_contigmem, OID_AUTO, buffer_size, CTLFLAG_RD,
  68         &contigmem_buffer_size, 0, "Size of each contiguous buffer");
  69 SYSCTL_INT(_hw_contigmem, OID_AUTO, num_references, CTLFLAG_RD,
  70         &contigmem_refcnt, 0, "Number of references to contigmem");
  71
  72 static SYSCTL_NODE(_hw_contigmem, OID_AUTO, physaddr, CTLFLAG_RD, 0,
  73         "physaddr");
  74
  75 MALLOC_DEFINE(M_CONTIGMEM, "contigmem", "contigmem(4) allocations");
  76
  77 static int contigmem_modevent(module_t mod, int type, void *arg)
  78 {
  79         int error = 0;
  80
  81         switch (type) {
  82         case MOD_LOAD:
  83                 error = contigmem_load();
  84                 break;
  85         case MOD_UNLOAD:
  86                 error = contigmem_unload();
  87                 break;
  88         default:
  89                 break;
  90         }
  91
  92         return error;
  93 }
  94
  95 moduledata_t contigmem_mod = {
  96         "contigmem",
  97         (modeventhand_t)contigmem_modevent,
  98         0
  99 };
 100
 101 DECLARE_MODULE(contigmem, contigmem_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
 102 MODULE_VERSION(contigmem, 1);
 103
 104 static struct cdevsw contigmem_ops = {
 105         .d_name         = "contigmem",
 106         .d_version      = D_VERSION,
 107         .d_flags        = D_TRACKCLOSE,
 108         .d_mmap_single  = contigmem_mmap_single,
 109         .d_open         = contigmem_open,
 110         .d_close        = contigmem_close,
 111 };
 112
 113 static int
 114 contigmem_load()
 115 {
 116         char index_string[8], description[32];
 117         int  i, error = 0;
 118         void *addr;
 119
 120         if (contigmem_num_buffers > RTE_CONTIGMEM_MAX_NUM_BUFS) {
 121                 printf("%d buffers requested is greater than %d allowed\n",
 122                                 contigmem_num_buffers, RTE_CONTIGMEM_MAX_NUM_BUFS);
 123                 error = EINVAL;
 124                 goto error;
 125         }
 126
 127         if (contigmem_buffer_size < PAGE_SIZE ||
 128                         (contigmem_buffer_size & (contigmem_buffer_size - 1)) != 0) {
 129                 printf("buffer size 0x%lx is not greater than PAGE_SIZE and "
 130                                 "power of two\n", contigmem_buffer_size);
 131                 error = EINVAL;
 132                 goto error;
 133         }
 134
 135         for (i = 0; i < contigmem_num_buffers; i++) {
 136                 addr = contigmalloc(contigmem_buffer_size, M_CONTIGMEM, M_ZERO,
 137                         0, BUS_SPACE_MAXADDR, contigmem_buffer_size, 0);
 138                 if (addr == NULL) {
 139                         printf("contigmalloc failed for buffer %d\n", i);
 140                         error = ENOMEM;
 141                         goto error;
 142                 }
 143
 144                 printf("%2u: virt=%p phys=%p\n", i, addr,
 145                         (void *)pmap_kextract((vm_offset_t)addr));
 146
 147                 mtx_init(&contigmem_buffers[i].mtx, "contigmem", NULL, MTX_DEF);
 148                 contigmem_buffers[i].addr = addr;
 149                 contigmem_buffers[i].refcnt = 0;
 150
 151                 snprintf(index_string, sizeof(index_string), "%d", i);
 152                 snprintf(description, sizeof(description),
 153                                 "phys addr for buffer %d", i);
 154                 SYSCTL_ADD_PROC(NULL,
 155                                 &SYSCTL_NODE_CHILDREN(_hw_contigmem, physaddr), OID_AUTO,
 156                                 index_string, CTLTYPE_U64 | CTLFLAG_RD,
 157                                 (void *)(uintptr_t)i, 0, contigmem_physaddr, "LU",
 158                                 description);
 159         }
 160
 161         contigmem_cdev = make_dev_credf(0, &contigmem_ops, 0, NULL, UID_ROOT,
 162                         GID_WHEEL, 0600, "contigmem");
 163
 164         return 0;
 165
 166 error:
 167         for (i = 0; i < contigmem_num_buffers; i++) {
 168                 if (contigmem_buffers[i].addr != NULL)
 169                         contigfree(contigmem_buffers[i].addr,
 170                                 contigmem_buffer_size, M_CONTIGMEM);
 171                 if (mtx_initialized(&contigmem_buffers[i].mtx))
 172                         mtx_destroy(&contigmem_buffers[i].mtx);
 173         }
 174
 175         return error;
 176 }
 177
 178 static int
 179 contigmem_unload()
 180 {
 181         int i;
 182
 183         if (contigmem_refcnt > 0)
 184                 return EBUSY;
 185
 186         if (contigmem_cdev != NULL)
 187                 destroy_dev(contigmem_cdev);
 188
 189         if (contigmem_eh_tag != NULL)
 190                 EVENTHANDLER_DEREGISTER(process_exit, contigmem_eh_tag);
 191
 192         for (i = 0; i < RTE_CONTIGMEM_MAX_NUM_BUFS; i++) {
 193                 if (contigmem_buffers[i].addr != NULL)
 194                         contigfree(contigmem_buffers[i].addr,
 195                                 contigmem_buffer_size, M_CONTIGMEM);
 196                 if (mtx_initialized(&contigmem_buffers[i].mtx))
 197                         mtx_destroy(&contigmem_buffers[i].mtx);
 198         }
 199
 200         return 0;
 201 }
 202
 203 static int
 204 contigmem_physaddr(SYSCTL_HANDLER_ARGS)
 205 {
 206         uint64_t        physaddr;
 207         int             index = (int)(uintptr_t)arg1;
 208
 209         physaddr = (uint64_t)vtophys(contigmem_buffers[index].addr);
 210         return sysctl_handle_64(oidp, &physaddr, 0, req);
 211 }
 212
 213 static int
 214 contigmem_open(struct cdev *cdev, int fflags, int devtype,
 215                 struct thread *td)
 216 {
 217
 218         atomic_add_int(&contigmem_refcnt, 1);
 219
 220         return 0;
 221 }
 222
 223 static int
 224 contigmem_close(struct cdev *cdev, int fflags, int devtype,
 225                 struct thread *td)
 226 {
 227
 228         atomic_subtract_int(&contigmem_refcnt, 1);
 229
 230         return 0;
 231 }
 232
 233 static int
 234 contigmem_cdev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 235                 vm_ooffset_t foff, struct ucred *cred, u_short *color)
 236 {
 237         struct contigmem_vm_handle *vmh = handle;
 238         struct contigmem_buffer *buf;
 239
 240         buf = &contigmem_buffers[vmh->buffer_index];
 241
 242         atomic_add_int(&contigmem_refcnt, 1);
 243
 244         mtx_lock(&buf->mtx);
 245         if (buf->refcnt == 0)
 246                 memset(buf->addr, 0, contigmem_buffer_size);
 247         buf->refcnt++;
 248         mtx_unlock(&buf->mtx);
 249
 250         return 0;
 251 }
 252
 253 static void
 254 contigmem_cdev_pager_dtor(void *handle)
 255 {
 256         struct contigmem_vm_handle *vmh = handle;
 257         struct contigmem_buffer *buf;
 258
 259         buf = &contigmem_buffers[vmh->buffer_index];
 260
 261         mtx_lock(&buf->mtx);
 262         buf->refcnt--;
 263         mtx_unlock(&buf->mtx);
 264
 265         free(vmh, M_CONTIGMEM);
 266
 267         atomic_subtract_int(&contigmem_refcnt, 1);
 268 }
 269
 270 static int
 271 contigmem_cdev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
 272                 vm_page_t *mres)
 273 {
 274         vm_paddr_t paddr;
 275         vm_page_t m_paddr, page;
 276         vm_memattr_t memattr, memattr1;
 277
 278         memattr = object->memattr;
 279
 280         VM_OBJECT_WUNLOCK(object);
 281
 282         paddr = offset;
 283
 284         m_paddr = vm_phys_paddr_to_vm_page(paddr);
 285         if (m_paddr != NULL) {
 286                 memattr1 = pmap_page_get_memattr(m_paddr);
 287                 if (memattr1 != memattr)
 288                         memattr = memattr1;
 289         }
 290
 291         if (((*mres)->flags & PG_FICTITIOUS) != 0) {
 292                 /*
 293                  * If the passed in result page is a fake page, update it with
 294                  * the new physical address.
 295                  */
 296                 page = *mres;
 297                 VM_OBJECT_WLOCK(object);
 298                 vm_page_updatefake(page, paddr, memattr);
 299         } else {
 300                 /*
 301                  * Replace the passed in reqpage page with our own fake page and
 302                  * free up the original page.
 303                  */
 304                 page = vm_page_getfake(paddr, memattr);
 305                 VM_OBJECT_WLOCK(object);
 306 #if __FreeBSD__ >= 13
 307                 vm_page_replace(page, object, (*mres)->pindex, *mres);
 308 #else
 309                 vm_page_t mret = vm_page_replace(page, object, (*mres)->pindex);
 310                 KASSERT(mret == *mres,
 311                     ("invalid page replacement, old=%p, ret=%p", *mres, mret));
 312                 vm_page_lock(mret);
 313                 vm_page_free(mret);
 314                 vm_page_unlock(mret);
 315 #endif
 316                 *mres = page;
 317         }
 318
 319         page->valid = VM_PAGE_BITS_ALL;
 320
 321         return VM_PAGER_OK;
 322 }
 323
 324 static struct cdev_pager_ops contigmem_cdev_pager_ops = {
 325         .cdev_pg_ctor = contigmem_cdev_pager_ctor,
 326         .cdev_pg_dtor = contigmem_cdev_pager_dtor,
 327         .cdev_pg_fault = contigmem_cdev_pager_fault,
 328 };
 329
 330 static int
 331 contigmem_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size,
 332                 struct vm_object **obj, int nprot)
 333 {
 334         struct contigmem_vm_handle *vmh;
 335         uint64_t buffer_index;
 336
 337         /*
 338          * The buffer index is encoded in the offset.  Divide the offset by
 339          *  PAGE_SIZE to get the index of the buffer requested by the user
 340          *  app.
 341          */
 342         buffer_index = *offset / PAGE_SIZE;
 343         if (buffer_index >= contigmem_num_buffers)
 344                 return EINVAL;
 345
 346         if (size > contigmem_buffer_size)
 347                 return EINVAL;
 348
 349         vmh = malloc(sizeof(*vmh), M_CONTIGMEM, M_NOWAIT | M_ZERO);
 350         if (vmh == NULL)
 351                 return ENOMEM;
 352         vmh->buffer_index = buffer_index;
 353
 354         *offset = (vm_ooffset_t)vtophys(contigmem_buffers[buffer_index].addr);
 355         *obj = cdev_pager_allocate(vmh, OBJT_DEVICE, &contigmem_cdev_pager_ops,
 356                         size, nprot, *offset, curthread->td_ucred);
 357
 358         return 0;
 359 }